<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form action="/user/login" target="_self">
    <p>请输入用户名</p>
    <p><input name="username"></p>
    <p><button>登录</button></p>
</form>
</body>
</html>